EME173-Ver1 Preamplifier Kits
- EME173 PC board Description:
Updated! June 2022! - EME173A6 Kit Notes:
- EME173A2 Kit Notes:
- EME173A70 Kit Notes:
- Mounting In A Die cast Enclosure:
- EME173 Kit Performance Tests:
- Kit changes and Updates:
- Buy A replacement EME173-R3 Series Kit:
The EME173 PC board was designed to suit the construction of receive only preamplifiers for the 30 to 500MHz bands. All Kits use the low cost BF998 MesFET from NXP that has a low noise figure and were designed for television tuners. The output of the BF998 is matched to 50ohms using a tapped inductor ensuring stable operation. The preamplifiers can all be adapted for frequencies outside the ranges specified for each product, by simply changing the turns on the input inductor. The upper range of the EME173A70 Kit however is around 500MHz maximum.
The Preamplifier has been designed to be easy to construct, and can be centre frequency tuned for use between 45 and 65MHz, and is suitable for the 50-54MHz Amateur Band. A low cost BF998 MesFET has been used as it has very good characteristics on the VHF to UHF bands. The BF998 was specifically designed for television tuners, and has a low noise and1dB NF at 800MHz along with high cross modulation performance. The BF998 incorporates integrated gate input protection diodes to help prevent damage to the device from static. The Preamplifier design is essentially a tuned input MesFET, with a wide band 50ohm matching transformer on the output. The Preamplifier however can also be used on a 75ohm antenna, or coaxial cable systems.
Top view of the EME173A6 6m Preamplifier
Fitting of the input inductor L1 for 50MHz
How to position the output matching transformer L2.
Fitting of the optional inductor L3 for DC power via the coaxial cable.
How to solder coaxial cable to the board when connectors are not required.
The Preamplifier has been designed to be easy to construct, and can be centre frequency tuned for use between 115 and 180MHz, and is suitable for the 144-148MHz Amateur Band. A low cost BF998 MesFET has been used as it has very good characteristics on the VHF to UHF bands. The BF998 was specifically designed for television tuners, and has a low noise and1dB NF at 800MHz along with high cross modulation performance. The BF998 incorporates integrated gate input protection diodes to help prevent damage to the device from static. The Preamplifier design is essentially a tuned input MesFET, with a wide band 50ohm matching transformer on the output. The Preamplifier however can also be used on a 75ohm antenna, or coaxial cable systems.
Top view of the EME173A2 2m Preamplifier
Fitting of the input inductor L1 for 144MHz
How to position the output matching transformer L2.
Fitting of the optional inductor L3 for DC power via the coaxial cable.
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How to solder coaxial cable to the board when connectors are not required.
The Preamplifier has been designed to be easy to construct, and can be centre frequency tuned for use between 350 and 500MHz, and is suitable for the 430-450MHz Amateur Band. A low cost BF998 MesFET has been used as it has very good characteristics on the VHF to UHF bands. The BF998 was specifically designed for television tuners, and has a low noise and1dB NF at 800MHz along with high cross modulation performance. The BF998 incorporates integrated gate input protection diodes to help prevent damage to the device from static. The Preamplifier design is essentially a tuned input MesFET, with a wide band 50ohm matching transformer on the output. The Preamplifier however can also be used on a 75ohm antenna, or coaxial cable systems. BUY THIS PRODUCT
Top view of the EME173A70 70cm Preamplifier
Fitting of the input inductor L1 for 144MHz
How to position the output matching transformer L2.
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Fitting of the optional inductor L3 for DC power via the coaxial cable.
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How to solder coaxial cable to the board when connectors are not required.
EME173A6 Preamplifier Gain and Bandwidth Test
EME173A6 Input Return Loss
EME173A2 Preamplifier Gain and Bandwidth Test
EME173A2 Input Return Loss
EME173A70 Preamplifier Gain and Bandwidth Test